Part time skimming with vodka dosing

[Moort82]

Apologise if this has been mentioned before as i know the subject has been discussed in length but does anyone dose vodka or another carbon source but not run their skimmer 24/7?
The tank is turning into a nps system and due to the heavier feeing i'm looking at ways to keep the nutrient levels down. The skimmer doesn't run all the time as its in a bedroom. The feeding happens through dosers throughout the whole day but more so when the skimmer is off. The plan would be to dose the vodka slightly before the skimmer first comes on and then 8 hours later or so.
Do you foresee a problem with this? I've seen most people run with a skimmer constantly on but have seen tanks dosing with no skimmer at all. The excess bacteria would be a good food source and i'm thinking a lower than normal dosing regime might work well but would love people opinions etc.

TIA

 

[swcc]

part time skimming is not a good idea...vodka dosing or not. taking your one 24/7 export off line, then saying you want to keep nutrients as low as possible are the complete opposite of each other. So, dosing or not...run it 24/7. And hopefully it is not off during the night...that is when a skimmer is actually most active.

 

[Moort82]

The skimmer is off at night and in fact its been off for the last year. Nutrinent level are low enough to have good sps growth as the filtration is very natural.
The skimmer is designed to help with the increase in food and the carbon source for two reasons. 1 so i can feed heavier and not effect the levels too much although maintanence will be increased as well. 2 i'm wanting to promote extra bactrial populations, again for a food source.

I know running the skimmer part time should hav no ill effects. It is very oversized and the manufacturers advise it can be ran on a timer as within a few hours it will catch up with itself. So the only issue i'm worried about is the increase of bacterial using up oxygen in the water without the skimmer to remove it when the skimmer is off. Since people have ran carbon dosing without a skimmer, at the low levels i'm proposing i don't think there will be a huge issue but i'd rather be sure than risk the livestock. So i guess the question is more, how long do bactrial populations boom after the introduction of a carbon source. Are they maintained at a high population or is there a change throughout the day?

 

[swcc]

bacteria are always in a stat of flux as nutrients rise and fall. So they increase and decrease. will the rise in bacteria increase co2 and cause problems...sure could. Every tank is a little different depending on just how much bacteria activity is happening in the first place. How long will bacterial population bloom? Hard to say, but, till nutrients become limiting to the point where the populations have to decrease..and when the nutrients are limited, bacteria will feed off the nutrients in dying bacteria... so any increase in nutrients will keep an increase in bacteria, and they will flux at higher levels than they are without the added nutrients. So, if you add carbon dosing, expect a 24/7 increase in bacteria counts over what they are now...
Will this cause a problem... without export...you bet(if not immediately.. over time)... it is the law of conservation of mass.
You cannot break the law of conservation of mass... what is imported must be exported for water nutrient levels to remain the same.
I would not look at the increased bacterial activity from carbon dosing as a source of food.
I would do as much research gathering on sucessful NPS reefers and follow what they do.

 

[jwoyshnar]

I agree with part time skimming except for while vodka dosing. You risk having a bacterial bloom which as mentioned will deplete your o2 levels to a dangerous level.

 

[Moort82]

bacteria are always in a stat of flux as nutrients rise and fall. So they increase and decrease. will the rise in bacteria increase co2 and cause problems...sure could. Every tank is a little different depending on just how much bacteria activity is happening in the first place. How long will bacterial population bloom? Hard to say, but, till nutrients become limiting to the point where the populations have to decrease..and when the nutrients are limited, bacteria will feed off the nutrients in dying bacteria... so any increase in nutrients will keep an increase in bacteria, and they will flux at higher levels than they are without the added nutrients. So, if you add carbon dosing, expect a 24/7 increase in bacteria counts over what they are now...
Will this cause a problem... without export...you bet(if not immediately.. over time)... it is the law of conservation of mass.
You cannot break the law of conservation of mass... what is imported must be exported for water nutrient levels to remain the same.
I would not look at the increased bacterial activity from carbon dosing as a source of food.
I would do as much research gathering on sucessful NPS reefers and follow what they do.

Thanks for that. At the moment the tank has a very large refugium which keeps the pH stable at night so deals with some C02. Its interesting what you say about bacterial levels, i'll take that on board.
I've done some more reading and together with your thoughts have come up with a new plan of action. The volume of water will be increased with an auto water change device or just an additional sump and the skimmer is to be plumbed into a room behind so it can be run 24/7.

Intresting that you say you wouldn't look at increased bacterial activity from carbon sourcing as food but i've seen a few people who swear by it with sea squirts and the like. So perhaps a happy coincidence.

 

[Moort82]

I agree with part time skimming except for while vodka dosing. You risk having a bacterial bloom which as mentioned will deplete your o2 levels to a dangerous level.

This was my original thought as well and the reason i asked the question in the first place. Always stayed away from methods like this due to the risks. The plan will be to do any changes super super slowly and hopefully minimise the need to change the way i'm currently running the system.

 

[swcc]

Intresting that you say you wouldn't look at increased bacterial activity from carbon sourcing as food but i've seen a few people who swear by it with sea squirts and the like. So perhaps a happy coincidence.

It may introduce more food, but do not count on it and reduce feeding is what I mean.

 

[Moort82]

It may introduce more food, but do not count on it and reduce feeding is what I mean.

I see, it was more for additional feeding if i was going to carbon dose. I'm hoping i can get away without it as the switch over will be slow, probably over the next year or two.

 

[bluewater921]

i dose vodka n run my skimmer all time .. the only time i turn my skimmer off is when i turn the pump off for feeding ..